Assembling and gluing for interlocking containers



Sept. 8, 1953 E. N BURNETT 5 L ASSEMBLING AND GLUING FOR INTERLOCKINGCONTAINERS Filed Oct. 3, 1950 11 She ets-Sheet 1 INVENTOR. EDWARD N.BURNETT ATTORNEYS p 53 E. N..:BURNETI 2,651,153

ASSEMBLING AND GLU ING FOR INTERLOCKING CONTAINERS Filed Oct. 3, 1950 l1Sheets-Sheet 2 INVENTOR. EDWARD N. BURNETT ATTORNEYS Sept. 8, 1953 E. NBURNETT I 2,651,153

ASSEMBLING AND GLUING FOR INTERLOCKING CONTAINERS Filed Oct. 3, 1950 l1Sheets-Sheet 3 q m N I I b H INVENTOR. v g3 EDWARD /v. sumvsrr I BYATTORNEYS 3 E. N. BURNETT 2,651,153

I ASSEMBLING AND GLUING F'OR INTERLOCKING CONTAINERS Filed om. 3,, 195011 Sheets-Sheet4 n n n n n n n n L 4 99196991918 2 u /we e 9,1 se /n vIN V EN TOR. EDWARD IV. BURNETT BY ATTORNEYS Sept. 8, 1953 r E. N.BURNETT. ASSEMBLING AND GLUING FOR INTERLOCKING CONTAINERS 11 Sheets-Sheet 5 Filed Oct. 5, 1950 INVENTOR. EDWARD N BURNETT ATTORNEYS P1953 v E. N. BUNETT 2,651,153

ASSEMBLING AND GLUING FOR INTERLOCKING CONTAINERS Filed Oct. 3, 1950 11Sheets-Sheet 6 INVENTOR. *3 EDWARD A/. BURNETT q. BY

fiqa dad r 1 n ATTORNEYS Sept. 8, 1953 E. N. BURNETT 2,651,153

ASSEMBLING AND GLUING FOR INTERLOCKING CONTAINERS- Filed Oct. 3, 1950 11She ets-Sheet 7 INVENTOR. EDWARD IV. BURNETT BY 70W M2M ATTORNEYS P 1953E. N. BURNETT 2,651,153

ASSEMBLING AND GLUING FOR INTERLOCKING CONTAINERS Filed Oct. 3, 1950 v11 Sheets-Sheet 8 l 0% I} q l W Lu- 1 H "G l l 1:: N {I} I l I a Q I I IW 3 I} \N I [H n I. l I" q a r" l I" 13 I N I Q l l "1 an I H *8! 1 Mine l i. l I l INVENTOR. EDWARD IV. BURNETT ATTORNEYS Sept. 8, 1953 E. N.BURNE'IT, 2,651,153

ASSEMBLING AND GLUING FOR INTERLOCKING CONTAINERS Filed 001:. 5, 195011" Sfie 'ets-Sheet 9 IN VEN TOR.

EDWARD IV. BURNETT A 7 TOR/V578 Sept.'8, 1953 E. N. BURNETT ASSEMBLINGAND GLUING FOR INTERLCCKING CONTAINERS 11 Sheets-Shed. 10'

Filed Oct-.- 5; .1950- T N W D M W E 47" ATTORNEYS E. N. BURNETT Sept.8, 1953 ASSEMBLING AND GLUING FOR INTERLOCKING CONTAINERS Filed Oct. 3,1950 ll Sheets-Sheet l1 INVENTOR. EDWARD 1v. BUR BY ATTORNEYS PatentedSept. 8, 1953 ASSEMBLING AND GLUING FOB INTER- LOCKING CONTAINERS EdwardN. Burnett, San Lorenzo, Calif., assignor to Gerber Products Company,Fremont, Mich., a corporation of Michigan Application October 3, 1950,Serial No. 188,254

18 Claims. (01. 53-3) This invention relates to new and usefulimprovements in methods and apparatuses for assembly of interlockingcontainers. More particularly, the invention relates to new and usefulmethods and machinery for assembling and gluing pairs of interlockingcontainer units, such as those disclosed in my copending patentapplication for Container Construction, Serial No. 141,150, filedJanuary 26, 1950.

Said copending application discloses novel container constructions inwhich two or more units are adapted to be interlocked together, one ofthe outer cover flaps of each unit having an integral projecting tongueand the other outer cover flap of each unit having a correspondingrecess receiving the tongue of the opposed unit. The top and bottomconstruction of the units are identical. Glue is applied to theundersurface of each tongue which adheres to the top surface of innerflaps which are exposed by reason of the recess cut in the outer flapwhich receives the tongue of the opposed box unit. The details of suchbox units are more completely described hereinafter in the body of thespecification of this application.

The instant invention has for its principal object the assembly andgluing of pairs of such container units. It will be assumed that theblank for each box unit has been folded at successive 90 angles alongscore lines therein provided as set forth in my said copendingapplications and that the meeting edges of the side panels have beenjoined by means of a strip of adhesive tape or other suitable attachingmeans to hold the adjacent panels together. The operator of the machinhereinafter described then forms a temporary bottom for each unit byfolding down all of the flaps thereof, but no glue is applied at thisstage of the assembly of the unit. Each unit is then filled withcontainers by means of a packing machine of substantially standardconstruction. The machine which is the subject of this invention thenperforms the following steps:

(A) Each filled unit is Packed, deposited on a conveyor belt andtransported into .the machine.

(B) Corresponding pairs of units are grouped together, the machine beingso constructed that two units are positioned with their opposed sidesabutting and are so conveyed that the two units proceed through themachine in such position. Th timing of this station of the machine issuch as to insure that units are paired together, and, if they are notso paired, further progress through the machine is halted untiladjustment is made. After release from this station, the

units are advanced through subsequent stages by a pusher bar bearingagainst the rear of the rearmost unit, release from the grouping stationbeing timed to movement of said bar.

(C) The inner top flaps of each unit are forced downwardly so that theyare horizontal and over lie the contents of the container.

(D) The outer top and bottom flaps are folded outward so that theyassume a horizontal position projecting away from the container.

(E) Glue is applied to the undersurfaces of the outer top and bottomflaps.

(F) The outer top and bottomfiaps are folded inwardly so that they arehorizontal and overlie the container.

(G) The container is subjected to compression so that the glue causesthe outer flaps of both the top and the bottom of each unit to adhere tothe inner flaps thereof, the projecting tongues of one unit adhering tothe portions of the inner flaps of the opposite unit exposed by thecutting away of recesses in the outer flaps.

(H Further compression is applied until the glue has set sufiicientlyfor handling.

Further objects of the present invention will become apparent uponreferring to the accompanying specification and drawings in whichsimilar characters of reference represent corresponding parts in theseveral figures of the drawmgs.

Fig. 1 is an exploded perspective view of two container units prior tobeing assembled together;

Fig. 2 is a perspective view of a pair of units as finally assembled;

Fig. 3 is a side elevation of the machine, which,

by reason of the space limitations, is included on' three sheets ofdrawings, the portions on each sheet being designated Figs. 3(a), 3(b)and 3(0) Fig. 4 is a side elevation of the unit assembly station andadjacent mechanism;

Fig. 5 is a top plan of the structure shown in Fig. 4.

Fig. 6 is a vertical section taken substantially Fig. 11 is a verticalsection taken substantially along the line IIII of Fig.

Fig. 12 is a wiring diagram of certain electrical circuits employed inthe unit assembly station;

Fig. 12: is a side elevationof an adjustable sprocket local-ted at the"forwardend of the first compression unit;

Fig. 14 is a section taken along the line I l-I4 of Fig. 13.

Fig. 15 is a side elevation of a roller-andsmounting mechanism which isa part of the inner'top flap closing station;

Fig. 16 is a top plan of thestrircture s'hotvr'r-in h Fig. 15;

Fig. 17 is a perspective view of the inner top flap closing station;

Fig. 18 is a perspective of a portion of the forward end of the outerflap refolding station;

Fig. 19 is a top plan of aportion. of the forward endfof the outer flaprefolding "station;

flii'g. 29 is aside elevationof 'a portion of the forward end ofthefirstcorhiirssion station.

Figs. 21 to 28, inclusive, are diagrammatic longitu dinal verticalfmidsections of a pair of container units "shown fat various stages intheir progress through the machine.

lteferring now to -Figs.f'1 and 2 there is illustrated-acontairierconstruction suchia's'that disclosed andfsetforth in myaforementioned'pateiit application, Serial No. 141,'150,'filed January23, 1950. It will beseenth'at the construction comprises two"interlocking box units indicated generallyby'refer'ence numerals XandY, formed of corrugated paper or other suitable material. Fig. 1 is "anexploded 'viewof thetw'o units prior to being ass emble d'together. InFig. 2. the two units "are shown in interlocked position. The sidesof'each box unit -forr'na rectangle in crosssection, "the respectivesides of which are indicated by'refere'nce numerals 2|, '22, 23, and 24.The meeting edges of'p'an'els 22 'and23 are held togetherbyas'trip-o'fgummed tape 25. The inner flapsof the top'fof'each unit, whichconstitute e i'tens'ioiispff-side'niembers 22 and 24, respectively,'afe'designated by reference numerals 21 and i213. -Said ihn'erflaps'are folded on horizontalls'core lin' es' disp'o'sed tramsea-Se to thedirection bfmbteiii'entbr the units through the machine, Said flaps meetalong the center of the box unit when rqiaea horizontal completed form."The outer'fiaps of the tops of eachofthe are designated by referencenumerals 2 9 anew Il' an d' constitute,' respectively, extensions ofside members ZI and 23. Said outer flaps are folded on "horizontalscoielines disposed paral- 11121 to 'the "'di'frection "or movement of theunits through the "machine. Outer top flap member 29 has-a projecting'tongue '3 I which projects out beyond the out-line of-side 24. Outer topflap member 30 has'a 'corresponding recess 32 cut thereinwhichie-dimensioned and positioned to receive the projecting tongue 3| of theopposite box-unit. =By reason ofth'e cutting away of the recess 32 inouter flap 30, .a portion of inner flap 28 is exposed prior to assemblyof the two units together, and when glue is applied to the underside ofthe; projecting tongue 3|, tongue 3i of one unit and flap 28 of thecooperating unit are.

joined and held together. One further feature of the structure of thebox units should be pointed out and that is that as most clearly shownin Fig. 1, one corner 33 of the inner top flap member '28 is cutaway toprovide stock for the projectin'g tongue 3|. This feature is illustratedprovided with a projecting tongue e ers containers "of otherconstruction, said machine is most'particularlyadapted for closing thecon- 4 and described in greater detail in my said ap-- plication, SerialNo. 141,150. The fact that said corner is cut away at 33 is utilized inthe assembly of the box units as hereinafter more fully appears.

It will be understood that the bottom of each box unit X and Y likewise"is fbiriied With two inner flaps I21 and I28 a-ndtw'o odtr fiaps I29and I30 and that outer flap I29 of each unit is NH, and outer haof eachunit is provided with a corresponding reess I32 to receive the tongueI3I of the opposite box unit.

Although the ri'ia'cliine which constitutes the ntention may be used toclose this invention comprises a-plu'ra1ity or seflfion's as hereinafterset forth:

A. Packer station -'of standard constructiom as well understood in theartt'o which this'invehtion pertains. Twenty fourcansaresimultaiieouslyand automatically inserted "in ea'chiirfit X or Y.

B. Unit assembly station whrein'each iinit is centered laterally of themachine -"-an"dthe two units of each pair are brought-together s'o'thatthe opposed sides are-abutting. Att'his station controls are provided sothat single units'w-ill-not proceed through them-achine separateiy' biitthat each pair will be grouped together and sieves through the machinetogether.

C. Inner top fiapc'losing statio'rifwherein'the inner top flaps arefolded down'so -that they assume a horizontalposition overlyingthe-contents of the container.

D. Top and bottom outer flap-uhfoldingsta tion. The outer flaps arefolded backward until they extend horizontally away from the containers.V d

I E. Gluing station wherein glue isapplied-to the under surfaces of theouter flaps.

F. Outer flap refolding station wherein the outer top flaps and theouterbotto'mflaps are folded back'so that theyassumea'hori'zontal'position overlying the inner top'and'b'ottom fia-psrespectively. 3 h g 7 G. First compression stationw'here'in the-pairs ofunits are moved by the conveyor 'b'ars' through a compression unit whichapplies'force tothfe top and bottom of the box so that theg'lue"wi'lladhere. 7

H. Second compression station f wherein 'further compression is applied."The units are moved through the machine byieonveyor' belts inconvention-almanner.

A. Packerstation This section of the machine is standard constructionand the 'detailsthereof are well'llinown in this art as exemplified'by'U. S. Lette'rs P tent 2,043,411 issued. June 9, 1936;afid2',I16,"793-isiid May 10, 1938. Box unit X or Y first is manually formedin rectangular shape and the bottom inner flaps I21 and I28 folded downand, the bottom outer flaps I29 and I30 foldedover said inner flaps, andthe top flaps 21, 28, 23 and 30 are open, or substantially vertical (seeFig. 1). The operator places the unit against the funnel or magazine 43of filler 42. The details of construction whereby twenty-four baby foodor other cans are simultaneously inserted into each unit are wellunderstood and constitute no part of the instant invention. After eachunit X or Y has been filled, the pivoted arm 4| is retracted by theoperator by actuation of pedal 40 so that the unit stands upright, andthe operator manually transfers the unit to endless moving belt 44 whichconveys the unit into the machine. The operator positions the box unitson belt 44 so that the leading unit X is positioned with tongues 3| andI3I projecting rearwardly and the next unit in order, Y, is positionedwith tongues 3I and I3I projecting forwardly so that units X and Y maybe properly joined together. If the operator errs so that the tongues 3|and I3I of unit X extend forwardly, a switch, hereinafter described,prevents further progress through the machines. The top stretch of saidbelt 44 is held substantially horizontally disposed by a plurality ofhorizontal idler rollers 46 having their axes transverse to thedirectionof movement of belt 44. The belt 44 is driven by driving roller41 around which the belt 44 passes at its forward end. Said drivingroller 41 bears a sprocket 48 at one end thereof which is connected bychain 49 to sprocket 5I on shaft 52. A second roller 53 is provided atthe opposite end of the conveyor belt 44 and said belt passes aroundsaid roller 53 at its rearward end. An adjustment device 54, as wellunderstood in this art, is provided to move said roller 53 relative toroller 41 and thereby tighten belt 46. Rollers 44, 41, and 53 are alljournaled in horizontal frame members 56 which extendlongitudinally ofthe machine and said frame members are supported by standards 51.

Shaft 52 is driven by means of sprocket 6| over which passes chain 62which, in turn, is driven by sprocket I49 on shaft 81, as herein-afterappears.

B. Um't assembly station At this station, shown in detail in Figs. 4 to7, the pairs of box units X and Y are assembled together so that theirside panels 24 abut and the tongues 3| and I3I of each unit overlap theopposite unit. It is very important that each pair of units beaccurately assembled with said sides 24 abutting and the units squarewith respect to each other since this relationship insures propersealing and interlocking of the units and prevents the units frombreaking apart during subsequent transportation, a result which wouldotherwise occur.

Accordingly, there are provided on opposite sides of the machine,horizontally disposed side members 65, which constitute extensions ofthe side members 56 of the packer station. Said side members 66 aresupported by standards, 61, the height whereof being adjustable as wellunderstood in this art. Eleven horizontally disposed sh-afts 68extending transversely across the machine are rotatably mounted in saidside members 66, the axes of all said shafts being level. Each shaft 68bears at each side of the machine a frusto-conical roller 69, vfixed forrotation with its shaft 68, the smaller end of the roller being directedinwardly. Opposed rollers 69 are spaced apart a distance such that asthe box units are discharged from conveyor belt 44 the opposite bottomside edges are supported by said frusto-conical rollers. In this mannerthe outer bottom flaps I29 and I30 sag slightly downward so as to assumean acute angle with respect to the bottom inner flaps I21 and I28. Thisinsures that the tongues I3I will overlap the opposite box unit; it alsoinsures that the platen of the gluer, hereinafter described, will passunder the outer flaps I29 and I30 so as to permit folding backward ofsaid outer flaps during passage through the gluer.

In order to insure proper passage of the units through the machine, ashereinafter appears, certain of shafts 63 are power driven and othersare idlers. Thus the first two shafts are idlers 68(I) and 68(2); thenext two shafts 68(3) and 68(4) are driven in unison; the next twoshafts 68(5) and 68(6) are idlers; and the last five shafts (38(1) to6'8( I I) are power driven in unison. Shafts 68(3) and 68(4) each bearsa sprocket II at one end which are driven by chain 12 which in turnpasses over sprocket 13 on shaft 52. Shaft 68(1) bears an idler sprocketI4 at one end over which passes chain I2. The opposite end of shaft63(1) and the correspondin ends of each of shafts 68(8), (9), and (I0)bear sprockets It over which passes chain 11 driven by sprocket "55 onshaft 52, thus resulting in shafts G8('l)-58(I8) turning in unison.Shaft 68(II) bears a sprocket I5 driven by chain I2, thus resulting inshaft 68(II) being driven at a slower speed than shafts 6=8('I)-68(I0).

Preferably shafts 68 are spaced apart a distance such that a single boxunit X is of a length two and one-half times the distance betweencenters of shafts 68. This spacing plus the alternation of driven andidler shafts 68 facilitates proper passage of the units through themachine. By timing mechanism hereinafter described, the leading edge ofeach leading unit X is held immediately above the center of shaft 68(II) until the trailing unit Y abuts unit X. Unit Y is pushed against unitX by a succeeding unit, which succeeding unit is urged forward by drivenrollers 69 on shafts 63(3) and 68(4). Upon actuation of certainswitches, later described, units X and Y are released and driven forwardby driven rollers 69 on shafts 68(l)--68(II). Any tendency of thesuceeding unit to follow after unit Y is prevented by reason of the factthat shafts 58 (5) and 68 (5) are not driven and thus the succeedingunit comes to rest. A brake I8, which is likewise described in detailbelow, further assists in preventing the succeeding unit from followingunit Y.

Similarly as a unit comes off the conveyor belt 44 it is pushed forwardby the succeeding unit until it is itself advanced by the rollers 56 onshafts 68(3) and 68(4) and in turn then pushes forward the unit aheadwhich is over the idler rollers 39 on shafts 68(5) and 68(6). The resultis that there is a gap between each unit except the abutting pair ofunits X and Y. The gaps between the other units permit entry ofmechanism to stop the units and prevents ganging of the units throughthe machine.

As has been stated, timing devices are incorporated in this section ofthe machine so that units X and Y are collected as a pair and each pairmoves through the machine together. Ac-

cordingly, stop members 8I are provided on op- I posite sides of themachine to hold the leading.

7 edges of the leading unit'X. Four switches 82-, 83, at, and as areprovided and an electrical cireuit is established so that when each ofsaid switches is closed, stop members 131 are retracted and the pair ofunits previously held thereby permitted to proceed through the machine.Limit switch 82 is provided adjacent stop members 8! and when theleading edge of the leading unit X comes to rest and is held by stopmember 8'! said switch 82 is closed. Limit switch 83 is provided so thatwhen the leading edge of the trailing unit Y of each pair comes to restabutting the trailing edge of the leading unit said switch is closed.The third switch 84 isac'tuated by cam 85 which rotates with conveyorbar sprocket shaft =87 hereinafter described, and said switch 85 is soactuated that the conveyor bars 88 will be in proper position to receivea pair of units when said switch is actuated. A fourth switch 85,normally closed, is provided in the path of the leading unit X beyondstops 89 (see Figs. 4 and If, by accident, unit X is turned around sothat tongue 13! projects forwardly, then switch 85 is opened and forwardprogress stopped until unit .X is turned around by the operator.

The electrical circuit for actuationof the solenoids {89 which retractthe stop members lil is shown diagrammatically in Fig. 12. Upon closingof switches 82 and 63 by front and rear unit-s X and "Y, respectively,and upon closing of switch 65, by timing cam-8'5 on conveyor shaft 8?,twop'ole relay i H is actuated to energize said soleholds 109 andrelease the units X and Y simultaneously in precise timed relationshipso that a conveyor bar 88 will come up behind the trailing unit Y andpush the two units X and Y through the gluer and compression units ofthe machine. It will further be seen from said wiring diagram Fig. 12that if a tongue i3! contacts switch 85 (by reason of unit X beingplaced in the machine in the wrong direction), then the electric circuitwhich energizes the relay HI is broken until the attendant places unit Xin proper direction.

After solenoids Hi9 are actuated, passage of units X and Y breakscontact at switches '82 and 83 with the result that the circuitenergizing said solenoids is broken. Rollers 93 roll along the "sidepanels of units X and hence do not interfere with movement of said unitsX and Y. Immediatcly after passage of unit Y, stop member 81 isinterposed to prevent passage of the succeeding unit.

Stop members 8| on opposite sides of the machine are identical inconstruction. A horizontal bar 9| is provided which terminates at itsinner end in a yoke shaped member 92, the arms of the yoke beingvertically disposed with respect to each other. Rollers 93 are providedto each of the legs of the yoke 82 and said rollers are disposed to bearagainst the box unit X and hold it against movement except when said barSi is retracted, as hereinafter explained. Bar 91 is horizontallydisposed within brackets 9'4 and 96 so that said bar may slide freelywithin the brackets in a horizontal direction transverse to thedirection of movement of the unit through the machine. Bar 91 is biasedinwardly by springs 91 which are helical in configuration and surroundhorizontal stub shafts 98. One end of each of the springs "97 bearsagainst stationary vertical brackets 99 and the opposite end bearsagainst a nut l0! which, in turn, bears against plate 102 to which bar9| is connected. Thus, the force of springs 97 is transmitted to plateI02 and thence to bar 91 and urges said bar inwardly. Chain I03 isoperatively connected to the bar 91 by means of threaded adjustmentmember 184 which is threaded into the end of bar 91 and thus by screwingthe threaded adjustment member m into or out of the end of the bar 91the effective length thereof may be adjusted. Chain 1 03 passes overidler sprocket IE3 and thence is connected to the upper end of thearmature 1118 of solenoid 1 69, said solenoid being vertically disposed.Upon energization of said solenoid We upon closing of switches 82, '83and chain 1'83 is pulled, which retracts bar 9| and thus permits a pairof units to move past stop members BI "into the gluing portion of themachine.

In order to prevent a succeeding unit from following unit Y through themachine upon release of the stop members 8|, brake 1-8 is provided. Saidbrake H8 is located with respect to stop member ll! 9. distancerearwardly slightly greater than the length of two units and on :oneside of the machine. Thus if a succeeding unit should be in placeimmediately to the rear of unit Y, upon actuation of said brake saidsucceedi-ng unit will be retarded so as not to "follow unit Yinto thegluer section. Brake 1%, as shown particularly in Figs. 4-6 comprises arubber-surfaced shoe 1 I 2 pivoted "at its rearward end on a verticalaxis "to a stationary plate H3 mounted on the side member '65. Ahorizontally slidable pin TM in said plate contacts and moves said shoeinwardly. Said pin r'lM is actuated upon actuation on solenoid W 9 asfollows: Link H6 is directly connected at one end to yoke -52; theopposite end of said 'li-n-k H6 is pivotally connected-toone end orrocker arm 1 11; rocker arm 11'? is pivotally mounted intermediate itsends to stationary member. 186; the end of rocker arm opposite link 1H5bears pin H'fl. Therefore, "retraction of stop member "8| results ininward movement of brake shoe 1'12 and thus holds up passage ofadditional units through the machine until stop niember 81 is restoredto position. Spring H5 biases said shoe H2 outwardly except whenbrakeflii is actuated. On the side of the machine opposite "brake "I8 isbrace i9 which 'restrains lateral displacement "of a 'box unit engagedupon actuation of .brake .18, the distance between brakelS "and'bra'ce19 being about equal to the width ref a box.

In order to insure proper :alignment of the units through tme assemblystation, at either side of the machine :there are provided horizontalside guides 12118 which are spaced apart a distance slightly :greaterthan the width of units X and Said rguides 21138 .are elevated above thesmacemfsroliers E9 aidistan'ce about equal to the height for :said units:by 'vertical standards :litB fixed :at their lower tends "to side."menibers'fifi. .The elevation of said guides 1 I8 is adjustable toaccommodate units of 'dilierent rlreights ianii ith'e :distanceibe'tween said guides is also adjustable my meason or horizontaltransversekoonnecting :mem'bcrs 129 which are fixed at zone end "togui'des Fl?! 8 :and :adjustably held at their dither-end brackets l 25!carriedby standand H29. .l rdsjiustm'ent er elevation is :accomplishe'dby reason "of "the fact that brackets '12! are adjustable or-1 standardH9.

tinuation of the station described 'in "the -'secltion' immediatelypreceding; except for certain modifications hereinafter mentioned, thestructure of this station resembles that corresponding station inKimball Pat. 2,095,258. Horizontal longitudinally disposed frame membersI36 at either side of the machine constitute continuations of the framemembers 66 of the preceding station. A roller table I31 is provided toreceive units X and Y upon release of stop members 8|. This tablecomprises a plurality of opposed pairs of idler rollers I38 supportedfrom said frame members I36, each said roller revolving upon a stubshaft I39 fixed to table I31. The axes of said shafts I39 are spacedalong a line inclined downwardly with respect to the horizontal and theaxes themselves are also inclined downwardly in the same fashion as thecorresponding rollers shown in Figs. 4 and 6 of Pat. 2,095,258. Hencewhen a pair of container units is released by the stop members BI itmoves by the force of gravity downwardly, being supported at its sideedges by said rollers. This manner of support preserves the downwardbending of flaps I29 and I30 and facilitates entry of platen I4I, ashereinafter appears.

On each side of the machine is a continuous roller chain I42 containedwithin tracks I43 affixed to the frame members, I36. Said chains I42 arearranged to be driven at equal speeds by sprockets I44 at opposite sidesof the forward end of said. machine (see Fig. 3c) said sprockets I44being fixed to transverse shaft I46 which shaft is, in turn, driven bymotor I41 through chain I 48. Chains I42 extend the entire length of thefolding, gluing, closing and compression stations from said sprocket I44to sprocket I49 at the rearward end of the flap closing station on shaft81. The upper stretch of each of said chains I42 is supported by saidtracks I43 and the lower stretch of the machine is supported by aplurality of idler sprockets II which are freely mounted on verticalsupports I52. An adjustable tensioning device I53 as wellunderstood inthis art is provided for chain I42. A plurality oftransversely-extending conveyor bars 88 is provided, opposite ends ofeach bar being attached to chains I42 at opposite sides of the machine.Said bars 88 are so positioned that they extend horizontal and normal tothe path of travel of the units through the machine. Thus, as the chainsI42 move at equal speed the bars 88 move through the machine. Said barsalong the upper course of movement arearranged to bear about midwaybetween the top and bottom of a container unit.

In order to insure that the conveyor bars 88 will be maintained exactlyperpendicular to the path of the units through the machine, anadjustment is provided to advance or retract one of the chains I42 withrespect to the other. Thus, as shown in Figs. 13 and 14 one of thesprockets I44 has an adjoining sidev plate l58 having a plurality ofarcuate slots through Which extend screws I51 which are fixed tosprocket I44. Plate I58 is keyed to shaft I46, to which shaft theopposite sprocket I44 is also keyed. Another arcuate slot I55 is cut inside plate I58, through which extends lug I59 welded to sprocket I44.Opposed adjusting screws I 60 carried by plate I58 bear against oppositesides of lug I59. Thus by loosening screws I51 and adjusting the angularposition of sprocket 444 with respect to plate I58, by the tightening ofone screw I68 and the loosening of the other. the position of sprocketsI44 relative to each other may. be adjusted and thereby one conveyorchain I42 maybe advanced 10 or retarded with respect to the oppositechain. In this manner the conveyor bars 88 may be squared.

Each conveyor bar 88 moves up behind the trailing container unit Y ofeach pair and pushes the pair of containers ahead through the inner flapfolding, gluing, outer fla closing, and compression stations of themachine. The pairs of container units are restrained against lateralmovement by means of horizontal, longitudinally disposed carton guidesii, there being two such guides on each side of the machine, the bottomguides I64 E) being spaced just above the bottom of a container unit andthe top guides I6I(2) being spaced just below the top of the containerunit. The distance between said guides I6I transversely of the machineis substantially equal to the width of the container units. Theconstruction and adjustabality of said guides is adequately set forth insaid Pat. 2,095,258. In order to prevent the outer flaps 29 and 38 ofthe container units, which normally are vertically disposed parallel tothe path of the container units through the machine, from interferingwith the closing of the inner flaps 21 and 28, flap guide I62 isadjustably held in position by means of bolts I63 passing through slotsI64 in the cross frame members I 66. Flap guides I82 extend from aposition adjacent the center of the machine at its rearward endoutwardly toward the side of the machine. Thus as flap 29 and 30 on oneside of each unit contact said guide I62 they are moved outwardly toassume a vertical position.

After the pairs of container units have been discharged from the taperedrollers I38 they move onto longitudinal horizontal platen I4I which isof restricted width less than the Width of the container units and sopositioned and arranged that the leading end thereof is inserted betweenthe outer bottom flaps I29 and I30 and inner bottom flaps I21 and I28 asthe container units are moved forwardly by the transverse conveyor bars88 by reason of the fact that the flaps hang downwardly. See Fig. 6 ofsaid Patent 2,095,258. Thus, the container units and their contents aresupported by means of the inner bottom flaps I 21 and I28 and the platenI4I on which the inner flaps I21 and I28 rest. V

The first step in the closing of the inner top flaps is the closing ofthe leading inner top flap 21 of the leading container unit X of eachpair.

Thi is accomplished by means of folding head I16 which is centrallydisposed with respect to the machine. As the leading container unit ispushed along by transverse conveyor bar 88, flap 21 contacts said headI16 and is pressed downwardly to a horizontal position overlying thecontents of the container unit. In order to providefor quick closing offlap 21 so that it does not interfere with rotation of flap closing arm"I, said head I16 is provided with a roller I11 at one side arrangedquickly to close flaps 21. Said roller I11 is held in position by nutI18 which is threaded over stud I19 extending from pivoted adjustmentplate IBI which is in turn supported by bracket plate I82. Pivotedadjustment plate I8! is pivoted at about its midpoint on bolt I83 andits end opposite stud I19 is provided with a slot I64 through whichpasses bolt I88. Bolts I83 and I36 are threaded into plate I32. Thus byadjusting the position of the slot I84 with respect to bolt I86, theheight of the roller I11 may be adjusted. Roller I11 is arranged toengage flap 21 of the leading container unit X and quickly 1 1 close itso as to assume a horizontal position. See Figs. 15 and 16.

At the same time that the leading flap 2? of leading unit X is beingclosed, the trailing flap 28 of the leading unit X is being closed byfirst flap closing arm I. See Fig. 17. Said arm III is supported androtated by a revolving disk I3I and is so positioned that its shank I92extends radially outwardly from said disk and its arcuate portion I 93has its radius of curvature concentric with said disk I9I. The outwardprojection of arm I'II may be adjusted by reason of shank I92 beingreceived in sleeve I95 on disk I9I and adjustably held by set screwI95a.

Disk I9I is mounted upon bracket I94 by means of bolt I96, said bracketI94 being connected to a stationary portion of the machine. Anadjustable clutch I9! is provided between disk I9I and sprocket I98 sothat the timing of the flap closing arms Ill and I12 may be adjusted.Sprocket I98 is driven by chain I99 which, in turn, passes over sprocketZiiI on shaft 292 to which is connected gear 263 which is driven by gear2% through the instrumentality of chain 295 passing over sprocket 291 onshaft 81 which bears conveyor chain sprocket I49. Thus, it will be seenthat the rotation of disk I9! is in carefully timed relationship withrespect to the advancement of the conveyor bars 88 through the machine.

As has been stated, leading flap 28 of unit Y is notched out asindicated by reference numeral 33 and this makes possible the movementof flap closing arm III as best illustrated in Fig. 17. The progress ofthe arm III is not impeded by flap 28 of unit Y because of the notchedportion 33 and hence the flap 28 of unit X may be closed by the flapclosing arm I'II, as flap ll of unit X is being closed by roller I". Itwill be understood that the plane of rotation of arm III is at the backof the machine as viewed in Fig. 8 and so positioned that arm III willpass through notch 33.

Further progress of the pairs of container units through the machineresults in the closing of the flap 28 of unit Y by roller I11 and headIIG as the pairs of units are advanced through the machine.

The remaining flap 2'! of unit Y is closed by the second flap closingarm I12 likewise mounted on disk I9I. Arm I12 is spaced angularly withrespect to arm III and so arranged that after arm III has closed flap 28of unit X, second arm I12 is in position to close flap 2! of unit Y.Clearance is provided between head I16 and bracket I32 for rotation ofarm I'I2. (See Fig. 16.)

The cooperative action of head I75 and roller IT! and the rotation ofarm I1! and second arm I72 results in the closing of the inner flaps 27and 28 of each of the units X and Y.

D. Top and bottom outer flaps unfolding station The next step in theprogress of the pairs of containers units through the machine is thefolding outward of outer top flaps 29 and 39 and the folding outward ofouter bottom flaps I 29 and I39. Carton guides I6! are so disposed thatthe upper edges of upper guide IGI (2) coincide with the score line atwhich the outer top flaps 29 and 38 are attached to the sides 2i and 23,and at the lower edge of lower guide II(I) coincides with the score lineat which the outer bottom flaps I29 and I39 are atached to the sides 2Iand 23. Thus, the carton guides I 6| provide a support along which thetop and bottom flaps may be folded backward away from the unit.

The folding backward of the flaps is accomplished by means of fourplowshares or horns 2H3, 2| I, 2I2, and H3, a pair of said plowsharesbeing disposed to fold backward the outer bottom upper plowshares 2 I0and 2I I at each side of the machine being arranged to fold backward theouter top flaps 29 and 39, and the bottom plowshares 2I2 and 2I3 at eachside of the machine being disposed to fold backward the outer bottomflaps I23 and I30. The shape and function of said plowshares is wellunderstood in this art and a detailed description thereof is deemedunnecessary. See especially Pat. 2,095,258. However, it may be statedthat the point of each plowshare moves inside the leading edge of theflaps 29, 39, I29, or I30 as the container units are moved through themachine by the transverse conveyor bars 88, and that by reason of thecurved or warped configuration of said plowshares, the flaps are bentoutwardly and extending horizontally away from the container. After theflaps have assumed a horizontal position, they are supported in saidhorizontal relationship by pressure plates 2I6 on their upper and lowersurfaces.

E. Gluing s ation As the containers pass through the gluing portions 2I8 of the machine, pairs of revolving rollers 2I3 at each side of themachine coated with liquid glue contact the undersurfaces of the outertop and bottom flap members 29, 39, I29, and I39 and apply a strip ofglue to said undersurfaces. This structure is illustrated in Pat.2,095,258. Cams 9% of said reference are preferably not used and glue isapplied continuously instead of discontinuously.

F. Outer flap refold ng station After the glue has been applied, theouter flaps 29, 38, I29, and I30 are folded back to normal position soas to overlie the inner flaps 27, 28, I21, and I 28, the inward foldingmovement being accomplished by means of a second series of fourplowshares or horns 22I, and 222 and two additional plowshares ofcomplementary shape on opposite sides of the machine (not shown) similarin appearance to those shown in Fig. b, two on each side of the machine,and comprising an upper and a lower plowshare for the upper and lowerouter flaps, respectively. The configuration and function of the secondset of plowshares is likewise well known in this art and a detaileddescription thereof is deemed unnecessary. See Pat. 2,095,258. After theouter flaps are positioned overlying the inner flaps the glue on theunder surfaces of said outer flaps causes adherence between the outerand inner flaps, and thus seals the top and bottom of each of thecontainer units. The individual units of each pair of containers areheld together by reason of the fact that glue has likewise been appliedto the undersurfaces of tongues 3I and I3I which tongues overlie theportion of flaps 28 and I28 which are exposed by reason of cutting awayof the recesses 32 and I32 in the flaps to and I30.

It will be understood, however, that the liquid glue which has beenapplied to the under-surfaces of the outer flaps does not setimmediately, and hence the units X and Y of each pair must be held inabutting position with their edges square and subjected to compressionin order to insure that the proper alignment of the two units of eachpair will be maintained until the glue has set .sufiiciently.

' squaring up the cases.

'- 13 The transverse conveyor bars 88 move the pairs of container unitslongitudinally of the machine between opposed horizontal closing plates23! and 232 centrally'disposed and extending longitudinally of themachine, one plate 232 being at the bottom of the machine and the otherplate 23! being at the top and spring biased downwardly by spring 229.Said plates act to apply pressure to the top and bottom of the unitsafter the outer flaps have been refolded and thus begin the applicationof compressive force to the containers, which force is continued in' thecompression unit which is immediately behind the gluing unit. In orderto position the containers centrally laterally of the machine, aplurality of flanged rollers 233 is provided with their axes disposedvertically. Said rollers revolving on stub shafts 234 which are fittedinto carton guide members, l6l( l) and [6| (2), said guide members beingspring biased inwardly by means of springs 23% surrounding stub shafts231, one end of said stub shafts 23'! being fixed to said guide membersit! and the opposite end of each shaft 231 being held within brackets23-8 fixed to stationary portions of the machine. Thus, the flanges ofthe upper set of rollers 233 engage the top of the box units and thecylindrical portions of said rollers engage the upper side edges of thecontainer and the flanges 239 of the bottom set of rollers 233 engagethe bottom of the box units and the cylindrical portions of said rollersengage the lower side edges of the containers. Hence the rollers 233maintain units Y and X in alignment laterally. The closing plate 23|extends to a point immediately adjacent the compression unit. The lowerclosing plate 232 picks up the boxes upon discharge from platen l M andcarries the units to the compression unit. In order to insure closing ofthe bottom flaps I29 and I30 a bifurcated curved support 24! isprovided, the rearward and lowermost parts of the arms 242 beingdisposed about one-quarter of the way inward from the sides and.engaging said flaps, particularly the flaps of unit Y and bringing themupward to be supported on bottom closing plate 232. A medial verticalfin 243 is provided at this portion of the machine to preventoverlapping of flaps 129 and I30 and to assist in See Fig. 18.

G. First compression station The compression unit which is used inconjunction with the present machine resembles standard compressionunits in common use at the present time with certain modificationsnecessitated by reason of the fact that this machine is designed to movea pair of container units together. In conventional compression unitsthere is provided a top and bottom continuous belt, the bottom beltbeing driven and adapted to carry the cases through the compressor. Theinstant machine diifers from conventional ones in that the pairs ofunits are conveyed through a first compression unit by means of the sametransverse conveyor bars 88 which convey the units through stations C toF. It will be understood that said transverse conveyor bars 88 are movedby the longitudinally extending continuous chains M2 at eithier side ofthe machine. This insures that the container units X and Y as they areconveyed through the compression unit by the bars 88 will remainabutting until the glue has set. The upper and lower belts 25! and 252between which the container units are moved are free to movelongitudinally of transverse conveyor bars 88.

the machine and are supported by a plurality of transverse horizontalrollers 253 which are journalled in the frame members 254 of thecompression unit. Said rollers 253 are spaced closer together on thebottom stretch than in conventional compression units to eliminateup-anddown movement. The upper set of rollers 253 are spring biaseddownwardly by springs255 to apply pressure on the tops of thecontainers, as in conventional compression units.

Spring loaded squaring rolls 256 are positioned to both sides of thefirst section of the compression unit and adjacent the top and bottomedges of the boxes. Said squaring rolls have vertical axes and aresupported by horizontal members 251 slidably received in horizontalsleeves 258 with springs 259 urging said squaring rolls 256 inwardly.Upper members 258 are, in turn, adjustably connected to vertical rods26! by brackets 262 so that inward and outward position of members 256may be adjusted. Brackets 263 receive rods 26l and are adjustable sothat the elevation of upper square rolls 25!; maybe adjusted.

Lower rolls 256 likewise have their axes vertical and held by horizontalrods 264 received slidably in sleeves 265 with springs 265a biasing saidrollers inwardly.

It will be observed that in order to maintain substantially horizontalmovement of the container units through the entire machine withoutvertical movement which might tend to separate the units one from theother, the compression unit is positioned as closely adjacent the glueras possible. This close spacing insures that the bottom of the containerunits will be supported almost continuously and thus eliminate thetendency of the container to break apart.

H. Second compression station As has been stated, the first compressionunit which is positioned immediately adjacent the gluer is not powerdriven but on the contrary the cases are moved through this unit bymeans of Immediately following the first compression station G is asecond compression station H and it will be understood that said secondcompression station H may be of standard construction in that the lowerbelt 256 is power driven and the cases are conveyed through said secondcompression unit by means of said lower belt. After the container unitshave passed through the first compression unit the glue is fairly Wellset, but an unevenness of transfer tends to break the cases apart. Inorder to insure evenness of transfer, a limit switch 251 is installed insuch position that the front end of the leading unit X contacts saidswitch as soon the back end of unit Y is released from belts 25| and252. The adjacent ends of belts 252 and :266 are spaced apart a distancegreater than the combined lengths of units X and Y. Said limit pressionstation to the second, the bottom belt first compression unit before thebottom belt of the second compression unit begins to move so that thereis no tendency of the two units to be pulled apart. Further, horizontalflap depressers 268 are provided to engage and hold down flaps 29 and 30during transfer from station G to station H. Said depressers 258 arehorizontal, transverse rollers' mounted in brackets 210 which aremounted on a horizontal, transverse axis to a stationary portion ofstation G. Depressers may rock upward as shown by dotted lines in Fig.20 to facilitate passage of the leading ends of unit X, but by reason ofgravity tend to hold down the top outer flaps. An idler roller 269 isalso provided in advance of lower belt 266 to engage the bottom of theunits and assist in holding them level during transfer.

After the container units have passed through the second compressionunit and such additional compression units as may be received, the gluehas set sufficiently for handling the two units of a pair without dangerof separation.

Method of operation The method which is the subject of this inventioninvolves the performance of the following steps, it being understoodthat one or more of the steps may be omitted and two or more of thesteps may be combined into a single step:

A. Packing-This is a conventional step which involves the filling ofeach unit of the several pairs of container units with cans, jars, orthe like. The units are first formed into rectangular shape and thebottoms temporarily formed without gluing by first folding inward thebottom inner flaps and then the bottom outer flaps. The units are filedin any convenient manner. The filled units are then deposited on amoving belt and conveyed into the machine, it being understood that theattendant places the first unit of each pair with projecting tonguesextending rearwardly and the second unit of each pair with theprojecting tongues extending forwardly.

B. AssembZing.In this step the pairs of units are brought together sothat the rearward panel of the leading unit and the forward panel of thesecond unit are tight together and the side edges of the two units aresquare. unit is stopped until the second unit is in proper place behindit; then the two units of the pair are released simultaneously in propertimed relationship to be picked up for movement through the subsequentsteps. Provision is made so that there is no release if the leading unitis turned in the wrong direction. The units are grouped as shown in Fig.21 after this step.

0. Closing inner top flaps.The pairs of units are moved forwardly bybeing pushed from the rear. The units are supported by a platen on whichthe inner bottom flaps rest. There are four inner top flaps in a pair ofunits, and these are closed sequentially. The leading inner top flap ofthe leading unit is first pressed down rearwardly. Fig. 22 shows theaccomplishment of this operation. The trailing inner top flap of theleading unit is then pushed down forwardly, the arm Ill clearing throughout out portion 33 of flap of the second unit, as shown most clearly inFig. 1'7. Fig. 23 shows the completion of this operation. The leadinginner top flap of the second unit is then pressed down rearwardly. Fig.24 shows the completion of this operation. Finally the trailing innertop flap of the second unit is pushed down forwardly, the unitsthereupon having assumed the position shown in Fig. 25. The inner top aswell as the inner bottom flaps have been closed at the end of this step.

D. Unfolding top and bottom outer flaps.By

The leading 16 means of conventional horns or plowshares the outer flapsare folded outwardly. Reference is made to said Pat. No. 2,095,258 forthe performance of this step, and particularly to Fig. 10 of saidreference.

E. GZuing.-Glue is applied to the undersurfaces of all of the outerflaps.

F. Refoldz'ng of outer flaps-By means of conventional horns orplowshares the outer flaps are folded inwardly to overlie and adhere tothe inner flaps. See Figs. 12 to 15, inclusive, of said Pat. No.2,095,258. It will be understood that the projecting tongues of theunits overlap the opposite unit and fit into the complementary recessesin the top flap of said opposite unit. The glue on the underside of thetongue adheres to the exposed inner flaps under the recess. Upon settingof the glue, the two units of the pair are locked together by means ofthe projecting tongues. See Fig. 2.

G. Initial compressing.setting of the glue is not instantaneous.Therefore compression must be applied until the glue has setsufficiently for further handling. In the first compression unit thepairs of units are pushed by force applied to the rear of the secondunit. Transfer into this step is shown in Fig. 26, it being understoodthat the units must be kept level at all times to prevent the units ofthe pairs working apart. Pressure is applied from the top and the bottomis held firm. Pressure is also applied inwardly from the sides to keepthe side edges square. Passage through this step is shown in Fig. 27

H. Second compressing.Further compression is applied to the top in orderto facilitate setting of the glue. During this stage the pairs of unitsare moved forwardly by means of moving belts as in conventionalmachines. Provision is made for level transfer from the first to thesecond compression stage. See Fig. 28. An electrical circuit isestablished such that the belt of the second compression stage movesforward only after the pair of units has cleared the first compressionunit so that there is no tendency to pull the units apart. Fig. 28illustrates passage of the units through the second compressing step.Thereafter the units may be handled as desired.

It will be noted as a matter of terminology that in the claims switch isreferred to as the third switch, and switch 84 is referred to as thefourth switch.

Although the present invention has been described in some detail by wayof illustration and example, it is understood that certain changes andmodifications may be made within the spirit of the invention and scopeof the appended claims.

I claim:

1. Machinery for use in closing pairs of interlocking container unitshaving transversely extending inner flaps and longitudinally extendingouter flaps, at least one of said outer flaps having a projecting tonguecomprising first means for assembling pairs of units with the trailingpanel of the first unit abutting the leading panel of the second unit,second means for advancing the assembled pairs of units, third means forfolding glued outer flaps over said inner flaps with said projectingtongue of one unit overlying the other unit, and fourth means forapplying compressive force to said pairs of units during drying of theglue during action of said second means.

2. Machinery for use in closing pairs of interlocking container unitshaving transversely extending inner flaps and longitudinally extendingouter flaps, at least one of said outer flaps hav- 17 ing a projectingtongue comprising first means for assembling pairs of units with thetrailing panel of the first unit abutting the leading panel of thesecond unit, second means for'advancing the assembled pairs of units,third means for closing each of the transversely extending inner fiapsof each unit, fourth means for folding glued outer fiaps over said innerflaps with said projecting tongue of one unit overlying the other unit,and fifth means for applying compressive force to said pairs of unitsduring drying of the glue during action of said second means. 1

3. Machinery as defined in claim 1 in which said second means advancessaid units ,both through said third and fourth means.

4. Machinery as defined in claim 2 in which said second means advancessaid units through said thrid, fourth and fifth means and which furthercomprises sixth means driven'by said second means and driving said thirdmeans in timed relation to movement of said second means.

5. Machinery for closing interlocking groups of container units of apredetermined number having transversely extending inner flaps andlongitudinally extending. outer flaps, an outer means for holding saidstop means inoperative responsive to the presence adjacent said leadingunit of a predetermined number of other units constituting the desiredgroup, means for advancing said groups of container units beyond saidassembly means, at least one conveyor member, means-for advancing saidconveyor member in a position behind the rear unit of each said group ofsaid units and pushing said group forwardly, inner top flap foldingmeans, gluing means for applying glue to the outer flaps and theprojecting tongue of one unit, outer flap folding means to glue saidinner and outer flaps together and the projecting tongue of one unit tothe adjacent unit, and compression mean for applying compressive forceuntil the glue has unit of each said group of units in timed relation tothe advancement of said group.

7. Machinery as defined in claim 5 wherein a brake is provided along thepath of travel of said units through said assembly means to restrain anyunit in excess of the predetermined number of units in said group fromadvancing through said assembly means.

8. Machinery as defined in claim 5 wherein second compression means areprovided to apply pressure for additional time until the glue hasfurther set, said second compression means including conveying meansindependent of said conveyor member.

9. Machiner as defined in claim 5 wherein second compression means areprovided to apply pressure for additional time until the glue hasfurther set, said second compression means including conveying meansindependent of said conveyor member, and wherein a level support isprovided to hold said units level during transfer 18 from said first tosaid second compression means.

10. Machinery as defined in claim 5 wherein areprovided-secondcompression means to apply pressure for additional timeuntil the, glue has further set, said second compression means includingconveying means independent of said conveyor member, a level support tohold said units level during transfer from said first to said secondcompression means, said firstand second compression means being spacedapart a distance greater than the length of said group of units, andmeans for causing motion of said conveying means of said secondcompression means after the rearmost unit has become disengaged fromsaid first compression means.

11. Machinery as defined in claim 5 wherein are provided secondcompression means to apply pressure for additional time until the gluehas further set," said second compression means in: cluding conveyingmoans independent of said conveyor member, and means to apply forceinwardly. against the sides of said units during passage through saidcompression units.

12. A method of forming a multiple unit. con

tainer comprising, providing a pair of container units, said unitshaving inner and outer closing flaps, atleast one of said units beingformed with one of its outer flaps having a projecting integral,

overlies the other unit and is joined thereto by said adhesive and holdssaid units together.

13. A method of packaging merchandise comprising, providing a pair ofcontainer units each having top and bottom inner and outer closingflaps, at least one of the outer flaps of one of said units having aprojecting tongue adapted to overlie a portion of the other unit,forming a temporary bottom for each unit by folding inward the bottominner and outer flaps, filling. said units, assembling said units injuxtaposed pairs with the adjacent unitsabutting with said projectingtongue'extending'over the outline of said other unit, folding inward thetop inner flaps of each unit, folding outward the top and bottom outerfiaps of each unit, applying adhesive to the undersurfaces of said topand bottom outer flaps, including the undersurface of said tongue, andfolding inward said top and bottom outer flaps and said tongue over saidother unit.

14. A method of packaging merchandise com prising, providing a pair ofcontainer units each having top and bottom inner and outer closingflaps, at least one of the outer fiaps of one of said units having aprojecting tongue adapted to overlie a portion of the other unit,forming a temporary bottom for each unit by folding inward the bottominner and outer flaps, filling said units, assembling said units injuxtaposed pairs with the adjacent units abutting with said projectingtongue extending over the outline of said other unit, folding inward thetop inner fiaps of each unit, folding outward the top and bottom outerflaps of each unit, applying adhesive to undersurfaces of said top andbottom outer flaps, including the undersurface of said tongue, andfolding inward said top and bottom outer flaps and said tongue over saidother unit, and applying compressive force against the top and sides ofsaid units while advancing said units by pushing from the rear.

15. A method of forming multiple unit con-

